Time for wall of text fun.
I am 34 and have been very happily married for 5 years now. My life would not be nearly as fulfilling without the wife that I hold dearly... and she was the first girl I ever dated.
Some people say 'oh, you are so lucky, the first girl you ever dated was the one for you' or even the more negative 'you must have pretty low expectations', but I assure you, neither is correct. It all comes down to approach.
Here is how I did it. Please note, what worked for me may not work for others, but I assure you, in my case, it worked well:
I have been interested in relationships for years before my first and only girlfriend and do not have problems courting or getting along with women. Despite this, I have strictly avoided entering a dating / physical relationship yet have made many many female friends. The reason for avoiding 'dating' someone romantically is simple, a spouse or girlfriend is often simply a great friend + physical fulfillment + commitment. I have always believed that the first step to a relationship should be friendship. Become friends, spend time together, talk to each other, and most importantly, become aware of each others values and attitudes. Think long and hard about who the person you are with is and be friends long enough (or at least know them long enough) to see past the mask most people put on in public. If you think this is the kind of person who you could spend most of your life with, then move to romance. If not, at least you have another friend with much fewer strings attached.
As a couple, the big issues are not dating, romancing and physical intimacy, the big challenge comes when you chose to live together and share responsibility. Can you spend all day everyday with your significant other without driving each other insane? Can you share major responsibilities and trust them? Can you hand over your credit card and share a bank account, with you SO? Can you tell them your secrets and everything with confidence in the fact that they will support you? If not, stop the relationship, and try again. Trying to 'make it work' is almost never a good idea when in all likelihood, there is someone out there for you.
Even if you find the love of your life, at most get engaged until both of you have finished your education, have found a job you can call a career, and life has settled to some degree. I gurentee you that until this point, you change dramatically in almost all cases. If you live a constantly changing dynamic unstable lifestyle, you may not be in the position to have children yet so why get married? Yes, marriage is a promise of commitment but is that so important if you trust your partner (and realize one or both of you may change) and you have no obligations to children? Children DO change the picture completely though, so be VERY careful there. When you have a child, a relationship is no longer simply about husband and wife or man and woman.